An emergency landing of a helicopter in the event of a turbine failure is performed according to the autorotation method. This method requires comprehensive training of the pilot and can be critical in a given flight situation and environment.
For this reason, certain helicopters are equipped with assistance systems based on a battery-powered electrical auxiliary drive. Such an assistance system makes a landing possible that is controlled to a large extent. As a result of the battery and motor technology, the costs and weight of this assistance system are very high.
Moreover, auxiliary drives are known that are based on a flywheel. For example, US patent document U.S. Pat. No. 4,609,165 discloses a helicopter in which a flywheel is used as an auxiliary power system.
A drive assembly for an automobile in which a detachable flywheel is integrated is described in German patent document DE 102009058695 A1. German patent document DE 102011014098 A1 describes a flywheel generator. A hybrid drive of an automobile with a flywheel as an energy store is known from German patent document DE 102004033039 A1. European patent document EP 1247736 A1 describes an aircraft in which motor output is used to rotate mechanical energy storage means. A power transmission device for helicopters is known, for example, from European patent document EP 0753456A1.